1. Field of the Invention
This specification relates to a method of sterilizing a water supply apparatus of a water purifier using electrolysis, and more particularly, a method of sterilizing a water supply apparatus capable of performing a circulation sterilization and a rinsing function using raw water at the same time.
2. Background of the Invention
In general, a water purifier is an apparatus that filters piped water supplied from a source of the piped water in physical and chemical manners to remove impurities and supplies the filtered water.
The water purifiers may be classified into a natural filtration type, a direct filtration type, an ion-exchange type, a distillation type, a reverse osmosis type and the like.
Also, the water purifier may be classified into a storage type water purifier that stores purified water passed through a filter in a water tank and then supplies the stored purified water in a heating or cooling manner, and a direct flow water purifier that supplies purified water passed through a filter in a heating or cooling manner without a water tank.
What is important in a driving water supply apparatus such as a water purifier is sanitation because it supplies at least one of purified water, cooled water or hot water that a person directly drinks.
However, when the water purifier is used for a long term of time, foreign materials may be likely to be stuck in an inner passage of the water purifier through which water flows, a valve, a coke and the like. This may lower sanitation due to the propagation of germs such as microbes.
In order to remove contaminants of the water purifier, a sterilizer may be mounted in the water purifier or provided separate from the water purifier and connected to the water purifier if necessary, so as to sterilize the water purifier.
For example, the sterilizers may be classified into a direct sterilizer that generates sterilizing water containing a sterilization material through electrolysis of water, generates sterilizing water using raw water, makes the generated sterilizing water flow into a water tank and simultaneously sterilizes and drains out the water, and a circulation sterilizer that circulates sterilizing water between a sterilization module and a water purifier so as to sterilize water, as disclosed in the following prior art document.
However, the related art sterilizer has the following problems.
First, when no water is filled in an electrolyzer during an initial generation of sterilizing water using electrolysis, it may cause damages on electrodes and an electrolyte membrane of the electrolyzer.
Second, when hot water is supplied to the electrolyzer during generation of sterilizing water through electrolysis of water, steam pressure of water increases and gas solubility decreases, thereby interfering with smooth generation of the sterilizing water.
Third, in order to sterilize floating bacteria which can be sterilized in a relatively high concentration of sterilizing water, the high concentration of sterilizing water has to be generated. To generate the high concentration of sterilizing water, an input current applied to the electrolyzer or an operation time of the electrolyzer should increase. This causes a shortened lifespan of the electrolyzer and a problem of exhaust ozone that ozone as a sterilizing material is discharged out of water. Therefore, a way of generating the high concentration sterilizing water even without increasing the applied current and the operation time of the electrolyzer should be considered.
Fourth, for a direct type water purifier, when air bubbles are present in a circulation passage connecting the water purifier and the sterilizer, the air bubbles may badly affect the electrolyzer while passing through the electrolyzer. For example, when the air bubbles are brought into contact with a metallic coating layer formed on the electrodes and the electrolyte membrane, the air bubbles burst, which causes the metallic coating layer to be peeled off.
Fifth, during sterilization of the direct type water purifier with a hot water tank therein, an operation of circulating sterilizing water along the hot water tank, as well as a purified water passage and a cold water passage is required.
Sixth, after sterilization of a water purifier, water tanks and passages have to be washed out, but the related art circulation type sterilizer has a circulation passage but does not separately employ a rinsing water passage and a drain passage, resulting in limitation of performing a rinsing (or washing) operation.